A method and structure for forming a continuous fiber-reinforced meniscus preform

Abstract

The application discloses a forming method and structure of a continuous fiber reinforced meniscus preform. The preform is integrally woven and formed, the circumferential yarn and the radial yarn are woven in a density gradient from inside to outside, the inside is sparse and the outside is dense, and the yarns are mutually laminated; the axial yarn is placed in the inside of the circumferential yarn and the radial yarn by using a Z-direction replacement mode and a loop locking edge, a path along the circumferential direction or the radial direction is formed, the axial yarn is placed in the inside of the circumferential yarn and the radial yarn, the layers of the woven structure are connected in series, a continuous fiber reinforced structure is formed, and the tensile and compression performance of the meniscus fabric can be improved. The specifications of the yarns in the meniscus structure can be flexibly selected to meet different load requirements; the meniscus structure has axial fibers, the layer connection effect is good, the circumferential fibers and the radial fibers can meet the similar biomechanical performance of the normal meniscus, and the service life of the meniscus is prolonged; the prepositioned fibers and the meniscus are integrally formed, the demand for the suture line of the meniscus in the later period can be net size profiling, the process is simple, and the forming efficiency is high.

Description

Technical Field

[0001] This invention belongs to the field of functional materials technology, and in particular relates to a method and structure for forming a continuous fiber reinforced meniscus preform. Background Technology

[0002] Meniscus injuries are difficult to repair on their own, and existing methods and repair materials are very limited. Traditional standardized meniscus implants use a single material, are isotropic, lack personalized design, and do not achieve the biomimetic structure of the human meniscus. They lack internal fiber reinforcement, making it difficult to meet joint biomechanical requirements, and their morphological characteristics cannot conform to the joint anatomy, easily leading to wear and inflammation, and their effective lifespan is less than 20 years. In contrast, fiber-reinforced meniscus fabrics can achieve anisotropic biomechanical characteristics through fiber structure design, effectively shortening surgery time and extending lifespan. The structure and composition of the meniscus are complex, making biomimetic fabrication a challenge. Meniscus prostheses must mimic the human meniscus in both materials and structure to adapt to the complex movements of the knee joint. Research and fabrication of artificial meniscus prostheses are currently a hot topic of interest.

[0003] There are numerous research findings both domestically and internationally. Patent CN107669373, "An Artificial Meniscus Scaffold Based on a Fiber Braided Structure and Its Braiding Method," discloses an artificial meniscus scaffold based on a fiber braided structure. However, the meniscus fabric reported in this patent lacks Z-axis fibers, resulting in poor fabric interlayer bonding. Patent CN115804865B, "A 3D-Printed Scaffold for Meniscus Replacement and Its Preparation Method," uses polymers to 3D print the meniscus scaffold; however, the fabric reported in this patent lacks Z-axis fiber reinforcement, leading to poor interlayer performance. Patent CN114214838B, "A Silk / Gel Multidirectional Fiber Sandwich Meniscus and Its Preparation Method," uses a silk fiber web as the core layer, with silk fabric as the upper and lower layers, sewn together with silk stitching. After impregnation with hydrogel and drying, a silk / gel multidirectional fiber sandwich meniscus is formed. However, the meniscus fabric reported in this patent is not integrally formed, resulting in low efficiency. Furthermore, the silk / gel multidirectional fiber sandwich meniscus lacks continuous circumferential and radial fibers, leading to poor mechanical properties and an inability to customize the meniscus shape. However, based on the biological structure of the meniscus, circumferential fibers are needed to improve the tensile strength of the meniscus (outer side), and radial yarns are needed to provide radial compressive strength. Patent US11813168B2, "Artificial Meniscus Including Circumferential and Non-Circumferential Fibers," reports an artificial meniscus comprising circumferential and non-circumferential fiber bundles. One direction of the raw material uses chemically synthesized materials, resulting in poor biocompatibility, and the fabric lacks personalized and customized design. Summary of the Invention

[0004] The purpose of this invention is to solve the problems mentioned in the background art and to propose a method and structure for forming a continuous fiber reinforced meniscus preform.

[0005] To achieve the objective of this invention, a method for forming a continuous fiber-reinforced meniscus preform is disclosed, comprising a meniscus preform composed of continuous circumferential fibers, radial fibers, and axial fibers, including the following steps:

[0006] Step 1: Raw material processing. The surface of the silk is modified by twisting and plying to change the yarn diameter and improve the yarn bundle properties.

[0007] Step 2: Based on the designed meniscus dimensions, design the mold row and column spacing M*N, and use 3D printing molds to achieve precise shape control of the outer surface and meet customization requirements;

[0008] Step 3: Design the yarn spacing and thickness according to the biological structure size and fiber content of the meniscus, so that the fiber arrangement is sparse inside and dense outside.

[0009] Step 4: During the weaving process, the yarn length and the specific design position are reserved along the circumferential and radial directions beyond the meniscus size. The yarn is in an "S" direction. In order to fix the reserved yarn and prevent slippage, the required weaving structure meniscus support is completed.

[0010] Step 5: The meniscus forming process mainly involves continuously weaving circumferential and radial yarns in a conformal manner, layering them together, and replacing the axial yarns in the Z direction. By using loop locking, the axial silk yarns are implanted into the circumferential and radial yarns, so that the weaving structures of each layer are connected in series, resulting in a continuous fiber-reinforced structure. This structure can improve the tensile and compressive strength of the meniscus fabric.

[0011] Step 6: Impregnate the obtained silk meniscus with hydrogel and encapsulate the biomaterial.

[0012] Furthermore, in step 1, the raw material is silk fiber with a fiber diameter of 20D~110D. The silk fiber is combined with multiple strands of balanced twist, and the fabric is non-toxic, harmless, and has good biocompatibility.

[0013] Furthermore, in step 2, the continuous contour weaving process of the circumferential and radial yarns is carried out on the weaving mold, on which Z-direction holes (1mm) are arranged and fine needles are inserted, and the circumferential and radial yarns are arranged in the gaps of the fine needle matrix respectively.

[0014] Furthermore, the mold material is one or more of the following: non-metallic polymer, metal, photosensitive resin, and inorganic non-metallic material.

[0015] Further, in step 3, based on the height h (mm) of the meniscus wedge shape and the outer circumference l, the number of meniscus unit layers n is designed. The width of the first unit layer is b1, the width of the second unit layer is b2, and so on, with the width of the nth unit layer being bn. The circumferential yarn spacing on the inner side of the meniscus is designed as k, and the radial yarn spacing is u. That is, the number of circumferential yarns in the first layer is (b1 / k) + 1, the number of circumferential yarns in the second layer is (b1 / k), and so on, with the number of circumferential yarns in the nth layer being (b1 / k) - (n-2). The number of radial yarns is (l / u) + 1, where (l / u) + 1 is an integer. Assuming that the circumferential yarn lengths are equal and l, the yarn length of the first unit layer is ((b1 / k) + 1) * l + ((l / u) + 1) * b1, and so on, with the yarn length of the second unit layer being (b1 / k) * b1. The length of the third layer of yarn is ((b1 / k)-1)*l+((l / u)+1)*b3, and the length of the nth layer of yarn is ((b1 / k)-(n-2))*l+((l / u)+1)*bn. Calculate the weight of each unit layer of yarn according to the yarn specifications, and obtain the fabric volume V according to the fabric model diagram. Then the fabric volume density is: p=m / V, where m is the sum of the weights of the n layers.

[0016] Furthermore, in step 5, during the replacement process, an automatic replacement device drives the fine needles and Z-direction fibers into the gaps inside the circumferential and radial yarns, replacing the fine needle matrix with continuous Z-direction fibers, thereby achieving automated edge locking of the coil.

[0017] Furthermore, axial yarn replacement can be performed along the radial or circumferential seam.

[0018] To achieve the objectives of this invention, this invention also discloses a continuous fiber reinforced meniscus preform structure. The meniscus preform structure is a biomimetic structure with morphological features that match the joint anatomy. It has a wedge-shaped appearance, with a lower inner surface and a higher outer surface, and is composed of three systems of yarns: axial yarn, radial yarn, and circumferential yarn.

[0019] Furthermore, the yarn ply ratio of the three systems can be arbitrarily adjusted, and the yarn center distance can be adjusted; the circumferential and radial fibers of the semi-menstrument prefabricated structure are continuously integrally formed.

[0020] Furthermore, the fiber volume content is 20%~25% and the fiber length is 50mm~100mm.

[0021] Compared with the prior art, the significant advancements of this invention are as follows: 1) This invention uses silk fibers to form an integrally woven meniscus structure. The yarn specifications in each direction of the meniscus structure can be flexibly selected to meet different load requirements; 2) The silk meniscus structure of this invention has axial fibers, resulting in excellent layering effect. The circumferential and radial fibers can meet similar biomechanical properties as a normal meniscus, improving the meniscus's resistance to delamination and shear resistance, and extending its service life; 3) The silk meniscus structure of this invention can have pre-placed fibers, and the pre-placed fibers and the meniscus are integrally formed, meeting the requirements of subsequent meniscus implantation sutures; 4) The preparation method of the silk meniscus of this invention is not limited by product size and shape. It can be dimensionally modeled, has a simple process, fast molding efficiency, and can be customized to meet different individual needs.

[0022] To more clearly illustrate the functional characteristics and structural parameters of the present invention, further explanation is provided below in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0024] Figure 1 This is a schematic diagram of the meniscus structure in this invention;

[0025] Figure 2 This is a schematic diagram of the composition of the meniscus yarn system in this invention;

[0026] Figure 3 This is a schematic diagram of the fine needle matrix principle in this invention;

[0027] Figure 4 This is a schematic diagram of the Z-axis permutation in this invention. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] like Figure 1-4 As shown, a method for forming a continuous fiber-reinforced meniscus preform, comprising continuous circumferential fibers, radial fibers, and axial fibers, includes the following steps:

[0030] Step 1: Raw material processing. The surface of the silk is modified by twisting and plying to change the yarn diameter and improve the yarn bundle properties.

[0031] Step 2: Based on the designed meniscus dimensions, design the mold row and column spacing M*N, and use 3D printing molds to achieve precise shape control of the outer surface and meet customization requirements;

[0032] Step 3: Design the yarn spacing and thickness according to the biological structure size and fiber content of the meniscus, so that the fiber arrangement is sparse inside and dense outside.

[0033] Step 4: During the weaving process, the yarn length and the specific design position are reserved along the circumferential and radial directions beyond the meniscus size. The yarn is in an "S" direction. In order to fix the reserved yarn and prevent slippage, the required weaving structure meniscus support is completed.

[0034] Step 5: The meniscus forming process mainly involves continuously weaving circumferential and radial yarns in a conformal manner, layering them together, and replacing the axial yarns in the Z direction. By using loop locking, the axial silk yarns are implanted into the circumferential and radial yarns, so that the weaving structures of each layer are connected in series, resulting in a continuous fiber-reinforced structure. This structure can improve the tensile and compressive strength of the meniscus fabric.

[0035] Step 6: Impregnate the obtained silk meniscus with hydrogel and encapsulate the biomaterial.

[0036] Example 1

[0037] Preparation of a silk-inspired bionic meniscus:

[0038] Step 1: Select degummed silk with a single linear density of 19 tex as the raw material for preparing the meniscus. Remove impurities from the surface of the silk through surface treatment and perform antibacterial treatment. Improve the yarn diameter, strength and bundle properties by plying 6 strands together.

[0039] Step 2: The designed meniscus dimensions are 20~6mm (radial) × 88mm (circumferential) × 6mm (height). The mold has 6*22 rows and columns. 3D printing technology is used to accurately replicate the outer surface of the meniscus according to its outer dimensions to achieve customized shape printing and precise shape control.

[0040] Step 3: The meniscus fiber volume content is 30%, the wedge shape height is 6mm, and the outer perimeter is 88mm. The design of the meniscus unit layers is 6, with the first layer having a width of 20mm, the second layer 18mm, the third layer 16mm, the fourth layer 13mm, the fifth layer 10mm, and the sixth layer 6mm. The design of the circumferential yarn spacing on the inner side of the meniscus is 2. The yarn diameter is 1 mm, the radial yarn spacing is 4 mm, meaning the number of circumferential yarns in layers 1-6 are 11, 10, 9, 8, 7, and 6 respectively, and the number of radial yarns is 23. Assuming the circumferential yarn lengths are equal, the unit layer yarn lengths for layers 1-6 are 1428 mm, 1294 mm, 1160 mm, 1003 mm, 846 mm, and 666 mm respectively. Since the silk is a 6-ply plied fabric, the weight of the yarn in layers 1-6 is 2.14 g. Based on the fabric model diagram, the fabric volume is 5.1 cm³, and the bulk density is 0.42 g / cm³.

[0041] Step 4: During weaving, in order to fix the pre-placed yarn and prevent slippage, the yarn is mainly laid in an "S" direction. According to the circumferential and radial directions, the yarn length beyond the half-meniscus size is reserved before laying the yarn, and the yarn is reserved at the design position to complete the laying of 6 layers of yarn.

[0042] Step 5: The circumferential and radial yarns are continuously woven in a conformal pattern and layered together. The axial yarn is introduced between the circumferential and radial yarns by an automatic replacement device with fine needles. The Z-axis yarn is introduced radially and the loops are used to lock the edges, so that the weaving structures of each layer are connected in series to obtain a continuous fiber-reinforced structure.

[0043] Step 6: Impregnate the obtained silk meniscus in a synthetic hydrogel to encapsulate the biomaterial.

[0044] Example 2

[0045] Preparation of a biomimetic meniscus made of nylon thread and silk:

[0046] Step 1: Select nylon yarn with a diameter of 2mm and a fiber specification of 12tex as the raw material for preparing the meniscus. Remove impurities from the surface of the silk through surface treatment, and improve the yarn diameter and bundle properties by plying 10 strands together.

[0047] Step 2: The designed meniscus dimensions are 12-2mm (radial) × 50mm (circumferential) × 1mm (height). Based on the outer box design of the meniscus, the mold row and column number is 5*28. Due to the compact size of this meniscus, 3D printing technology is used to replicate the meniscus's outer surface to ensure accurate shape reproduction, achieving customized contour printing and precise shape control.

[0048] Step 3: The meniscus fiber volume content is 15%, the wedge shape height is 2mm, and the outer circumference is 50mm. Based on the biomimetic meniscus height and fiber volume content, the number of unit layers of the meniscus is designed to be 5. The width of the first unit layer is 12mm, the width of the second unit layer is 10mm, the width of the third unit layer is 8mm, the width of the fourth unit layer is 5mm, and the width of the fifth unit layer is 2mm. The circumferential yarn spacing on the inner side of the meniscus is designed to be 1mm, and the radial yarn spacing is 2mm. That is, the number of circumferential yarns in the first to sixth layers are 13, 12, 11, 10, and 9 respectively, and the number of radial yarns is 26. Assuming that the circumferential yarn lengths are equal, the yarn lengths of the first to fifth unit layers are 962mm, 860mm, 758mm, 630mm, and 502mm respectively. The spider silk is 6 strands ply, so the weight of the first to sixth layers is 0.51g. Based on the fabric model diagram, the fabric volume is 2.6 cm³, and the bulk density of the fabric is 0.196 g / cm³.

[0049] Step 4: When weaving, fix the pre-placed yarn at the yarn return point to prevent slippage and lay it in an "8" direction. Lay the remaining part in a "U" shape. According to the circumferential and radial directions, reserve the yarn length beyond the half-meniscus size before laying the yarn and reserve the yarn at the design position to complete the laying of 5 layers of yarn.

[0050] Step 5: The circumferential and radial yarns are continuously woven in a conformal pattern and layered with each other. The axial yarn is made of 56tex silk fiber and is inserted into the circumferential and radial yarns by Z-direction replacement. Unlike Example 1, the axial yarn is introduced along the circumferential direction and an automatic replacement device is used to complete the automatic edge locking of the coil.

[0051] Step 6: Impregnate the obtained meniscus in a synthetic hydrogel to encapsulate the biomaterial.

[0052] Example 3

[0053] Preparation of a biomimetic meniscus made of silk thread

[0054] Step 1: Select non-absorbable silk suture with a linear density of 96 tex as the raw material for preparing the meniscus.

[0055] Step 2: The designed meniscus dimensions are 28~6mm (radial) × 112mm (circumferential) × 7mm (height). Based on the shape of the meniscus, the mold is designed with 6*22 rows and columns. 3D printing technology is used to replicate the shape of the meniscus to achieve customized shape replication printing and precise shape control.

[0056] Step 3: The meniscus fiber volume content is 20%, the wedge shape height is 7mm, and the outer perimeter is 114mm. The design of the meniscus unit layers is 6, with the first layer having a width of 28mm, the second layer 26mm, the third layer 23mm, the fourth layer 19mm, the fifth layer 14mm, the sixth layer 9mm, and the seventh layer 2mm. The circumferential yarn spacing of the meniscus is designed to be 2mm, and the radial yarn spacing is 6mm. m represents the number of circumferential yarns in layers 1-6: 15, 14, 13, 12, 11, 10, and 9, respectively, and the number of radial yarns: 19. Assuming equal circumferential yarn lengths, the unit layer yarn lengths for layers 1-6 are 2242mm, 2090mm, 1919mm, 1729mm, 1311mm, and 1064mm, respectively. Therefore, the weights of layers 1-6 are 0.215g, 0.200g, 0.184g, 0.166g, 0.126g, and 0.102g, respectively. Based on the fabric model diagram, the fabric volume is 3.7cm³, and the bulk density is 0.27g / cm³.

[0057] Step 4: During weaving, in order to fix the pre-placed yarn and prevent slippage, the yarn is mainly laid in an "8" direction. According to the circumferential and radial directions, the yarn length beyond the half-meniscus size is reserved before laying the yarn, and the yarn is reserved at the design position to complete the laying of 7 layers of yarn.

[0058] Step 5: The circumferential and radial yarns are continuously woven in a conformal pattern and layered together. The axial yarns are inserted into the circumferential and radial yarns by Z-direction replacement. The Z-direction yarns are introduced along the circumferential and radial directions of the fabric respectively. At the same time, loop sewing is used to form a series connection between the weaving structures of each layer, resulting in a continuous fiber-reinforced structure.

[0059] Step 6: Impregnate the obtained meniscus in a synthetic hydrogel to encapsulate the biomaterial.

[0060] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0061] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for forming a continuous fiber-reinforced meniscus preform, comprising a meniscus preform composed of continuous circumferential fibers, radial fibers, and axial fibers, characterized in that, Includes the following steps: Step 1: Raw material processing. The surface of the silk is modified by twisting and plying to change the yarn diameter and improve the yarn bundle properties. Step 2: Based on the designed meniscus dimensions, design the mold row and column spacing M*N, and use 3D printing molds to achieve precise shape control of the outer surface and meet customization requirements; Step 3: Design the yarn spacing and thickness according to the biological structure size and fiber content of the meniscus, so that the fiber arrangement is sparse inside and dense outside. Step 4: During the weaving process, allow for the yarn length and design location beyond the meniscus size along the circumferential and radial directions. The yarn follows an "S" direction to complete the required woven meniscus support structure. Step 5: The meniscus forming process mainly involves continuously weaving circumferential and radial yarns in a conformal manner, layering them together, and replacing the axial yarns in the Z direction. By using loop locking, the axial silk yarns are implanted into the circumferential and radial yarns, so that the weaving structures of each layer are connected in series, resulting in a continuous fiber-reinforced structure. This structure can improve the tensile and compressive strength of the meniscus fabric. Step 6: Impregnate the obtained silk meniscus with hydrogel and encapsulate the biomaterial; In step 2, the continuous contour weaving process of circumferential and radial yarns is carried out on a weaving mold. The mold is equipped with Z-direction holes and fine needles are inserted. The circumferential and radial yarns are arranged in the gaps of the fine needle matrix, respectively.

2. The method for forming a continuous fiber reinforced meniscus preform according to claim 1, characterized in that, In step 1, the raw material is silk fiber with a diameter of 20D~110D. The silk fiber is combined with multiple strands of balanced twist.

3. The method for forming a continuous fiber-reinforced meniscus preform according to claim 1, characterized in that, The mold material is one or more of the following: non-metallic polymer, metal, photosensitive resin, and inorganic non-metallic material.

4. The method for forming a continuous fiber-reinforced meniscus preform according to claim 1, characterized in that, In step 3, based on the wedge shape height h and outer perimeter l of the meniscus, the number of meniscus unit layers n is designed. The width of the first unit layer is b1, the width of the second unit layer is b2, and so on, with the width of the nth unit layer being bn. The circumferential yarn spacing on the inner side of the meniscus is designed as k, and the radial yarn spacing is u. That is, the number of circumferential yarns in the first layer is (b1 / k) + 1, the number of circumferential yarns in the second layer is (b1 / k), and so on, with the number of circumferential yarns in the nth layer being (b1 / k) - (n-2). The number of radial yarns is (l / u) + 1, where (l / u) + 1 is an integer. Assuming that the circumferential yarn length is equal to l, the yarn length of the first unit layer is ((b1 / k) + 1) * l + ((l / u) + 1) * b1, and so on, with the yarn length of the second unit layer being (b1 / k) * b1. The length of the third layer of yarn is ((b1 / k)-1)*l+((l / u)+1)*b3, and the length of the nth layer of yarn is ((b1 / k)-(n-2))*l+((l / u)+1)*bn. Calculate the weight of each unit layer of yarn according to the yarn specifications, and obtain the fabric volume V according to the fabric model diagram. Then the fabric volume density is: p=m / V, where m is the sum of the weights of the n layers.

5. The method for forming a continuous fiber-reinforced meniscus preform according to claim 1, characterized in that, In step 5, during the replacement process, the fine needles and Z-direction fibers are driven into the gaps inside the circumferential and radial yarns by an automatic replacement device, replacing the fine needle matrix with continuous Z-direction fibers, thereby realizing automated edge locking of the coil.

6. The method for forming a continuous fiber reinforced meniscus preform according to claim 5, characterized in that, Axial yarn replacement can be performed along the radial or circumferential edge.

7. A continuous fiber reinforced meniscus preform structure, said structure being based on a continuous fiber reinforced meniscus preform molding method according to any one of claims 1-6, characterized in that, The prefabricated meniscus structure is a biomimetic structure, with morphological features that match the joint anatomy. It is wedge-shaped, with a lower inner surface and a higher outer surface, and is composed of three systems of yarns: axial yarn, radial yarn, and circumferential yarn.

8. The continuous fiber reinforced meniscus prefabricated structure according to claim 7, characterized in that, The yarn ply ratio of the three systems can be adjusted arbitrarily, and the yarn center distance can be adjusted; the circumferential and radial fibers of the semi-menstrument prefabricated structure are continuously integrally formed.

9. A continuous fiber-reinforced meniscus prefabricated structure according to claim 7, characterized in that, The fiber volume content is 20%~25% and the fiber length is 50mm~100mm.

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